JP2000279439A - Laser operation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly position a laser irradiation and to track the movement of a patient by means of a simple configuration by providing a moving means for moving the position of a restriction member in a laser irradiation optical system and driving and controlling the moving means based on the detection result of a position detecting means by which the position of the patient is detected. SOLUTION: In the case of a cornea operation, the refraction force of the eye of the patient or an operation condition or the like is inputted by a computer 9, excision data of the cornea operation is calculated by the computer 9 and it is outputted to a control part. When a preparation is completed, the alignment of the patient eye is executed, an image signal from a CCD camera 24 is inputted to an image processing part 51 when an eyeball position is detected and a slit image projected on the cornea is detected. When the lesion position is moved in this case, aperture 13 is moved in an optical axis direction in accordance with the change, the projection image of the aperture 13 by a projection lens 16 is moved and also the diameter of the aperture 13 is changed, so that the change in projecting scale factor is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser surgical apparatus for performing treatment by irradiating a treatment laser beam to an affected part.

[0002]

2. Description of the Related Art As a laser operation apparatus for irradiating an affected part with a treatment laser beam for treatment, for example, a corneal operation apparatus using excimer laser light is known in the field of ophthalmology. This device irradiates the corneal surface with excimer laser light to cut off the diseased side of the corneal surface layer, or corrects the refractive error by cutting off the corneal surface and changing the corneal curvature.

In this type of apparatus, a fixation target is fixed on a patient's eye so as to irradiate a therapeutic laser beam to an intended position of the patient's eye, but is not moved at all. Is difficult. Therefore, even if the patient's eye moves during the operation, the laser irradiation optical system is automatically moved following the movement, and the laser irradiation is always performed at the intended position. It is proposed in, for example, Japanese Patent Application Laid-Open No. 9-149914.

[0004]

However, the above-described apparatus is configured to move the entire arm portion including the observation optical system and the laser irradiation optical system, and it is difficult to perform quick driving because the arm portion is heavy. For this reason, there has been a defect that quick alignment and poor followability with respect to a delicate movement of the patient's eye are inferior.

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the conventional apparatus, the present invention provides an ophthalmological apparatus capable of quickly aligning laser irradiation and tracking movement of an affected part with a simple configuration without moving the laser irradiation optical system in a large scale. It is an object of the present invention to provide a surgical apparatus.

[0006]

Means for Solving the Problems In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) In a laser operation apparatus having a laser irradiation optical system for irradiating a treatment laser beam to an affected part, position detecting means for detecting a position of the affected part to be irradiated with the treatment laser light, and the laser irradiation optics. A limiting member having a variable aperture diameter that limits an irradiation area of a laser beam with respect to an affected part, which is disposed in a system, a moving unit that moves a position of the limiting member in the laser irradiation optical system, and a detection result of the position detecting unit. And control means for controlling the driving of the moving means based on the control means.

(2) In the laser operation apparatus of (1), the moving means includes a plane direction moving means for moving the limiting member two-dimensionally in a plane direction orthogonal to the laser irradiation optical axis. .

(3) In the laser operation apparatus according to (1), the moving means moves the restricting member two-dimensionally in a plane direction orthogonal to the laser irradiation optical axis, and moves the restricting member with a laser. An axial moving unit that moves in the axial direction of the irradiation optical axis; the position detecting unit is a detecting unit that detects a three-dimensional position of the affected part; and the control unit is configured to detect a three-dimensional position detected by the position detecting unit. The control unit controls the driving of the plane-direction moving unit and the axial-direction moving unit on the basis of the control unit, and variably controls the diameter of the opening when the restricting member is moved in the axial direction.

(4) The laser surgery apparatus according to any one of (1) to (3) is characterized in that it is a corneal surgery apparatus which irradiates a cornea of a patient's eye with a laser beam in an ultraviolet region to ablate the cornea.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external view of an apparatus for performing corneal surgery using an excimer laser. 1 A surgical apparatus main body, in which an excimer laser light source and the like are built. Laser light from the excimer laser light source is reflected by a mirror in the main body 1 and guided to the arm 2. An observation optical unit 5 is provided at an end of the arm unit 2. The observation optical unit 5 includes a binocular microscope unit 3 for observing a patient's eye, an illumination unit 4, a laser irradiation port (not shown), and eyeball position detection. An optical system and the like are provided. The illumination unit 4 includes a visible light illumination light source that emits visible light for an operator to observe the patient's eye E, and an infrared light illumination light source.

As shown in FIG. 2, the arm 2 is moved in the X direction (in the left-right direction with respect to the operator) by the X drive 41, and in the Y direction (in the front-rear direction with respect to the operator) by the Y drive 42. )Moving. The observation optical unit 5 is moved in the Z direction (vertical direction: the axial direction of laser irradiation applied to the patient's eye) by the Z driving unit 43. Each of the driving units 41, 42, and 43 includes a motor, a slide mechanism, and the like.

Reference numeral 6 denotes a controller, which includes a joystick 7 for giving a signal for driving the arm 2 in the X and Y directions, a switch 60 for instructing the observation optical unit 5 to move in the Z direction, and the like. I have. Reference numeral 8 denotes a foot switch that sends a trigger signal for laser emission, and 9 denotes a computer that inputs various data of surgical conditions and calculates resection data. Reference numeral 10 denotes a patient bed.

FIG. 3 is a diagram showing an outline of an optical system and a control system of the apparatus. Reference numeral 11 denotes a laser light source that emits excimer laser light having a wavelength of 193 nm. The laser light emitted from the laser light source 11 is guided to the mirror 12 of the arm 2 via an optical system inside the main body. Reference numeral 13 denotes an aperture having a variable aperture diameter for limiting a laser irradiation area on the cornea. The aperture 13 is two-dimensionally moved by the aperture moving device 45 in a plane direction orthogonal to the center optical axis L of the laser irradiation optical axis, and is also moved in the axial direction of the optical axis L. FIG.
Is a view showing an example of a moving mechanism of the moving device 45. The aperture 13 is moved in the x direction by the motor 46, moved in the y direction by the motor 47, and moved in the z direction by the motor 48.
Moved in the direction. The opening diameter of the aperture 13 can be changed by the rotation of the motor 49.

The laser light passing through the aperture 13 is reflected by a mirror 14 arranged in the arm 2 and a mirror 15 arranged in the housing of the observation optical unit 5. Reference numeral 16 denotes a projection lens that projects the laser beam limited by the aperture 13 onto the cornea of the patient's eye. Reference numeral 17 denotes a dichroic mirror having a characteristic of reflecting excimer laser light and transmitting visible light and infrared light. The laser light having passed through the projection lens 16 is reflected by the dichroic mirror 17 and applied to the cornea of the patient's eye.

Above the dichroic mirror 17, the microscope section 3 and an eyeball position detecting optical system are arranged. Reference numeral 20 denotes an objective lens, and reference numeral 21 denotes a dichroic mirror having a characteristic of transmitting visible light and reflecting infrared light. An anterior eye image of a patient's eye passing through the dichroic mirror 21 can be observed by the binocular microscope unit 3. On the reflection side of the dichroic mirror 21, a mirror 22, an infrared transmission filter 23, a CCD
The camera 24 is arranged, and the imaging surface of the CCD camera 24 is arranged substantially conjugate with the vicinity of the pupil of the patient's eye with respect to the objective lens 20. Reference numeral 25 denotes a fixation lamp placed on the optical axis of the objective lens 20.

Slit projection optical systems 30a and 30b for alignment in the illumination unit 4 are arranged below the dichroic mirror 17 symmetrically with respect to the optical axis of the objective lens 20. Each slit projection optical system 30a, 30b includes lamps 31a, 31b, condenser lenses 32a, 32
b, cross-shaped slits 33a and 33b, and projection lenses 34a and 34b for projecting the slits onto the cornea of the patient's eye. The cross slits 33a, 33b are provided with projection lenses 34a,
It has a positional relationship conjugate with the cornea with respect to 34b, and the images of the left and right cross slits 33a and 33b are always formed at the focus positions on the optical axes of the microscope unit 3 and the objective lens 20. Reference numerals 35a and 35b denote infrared light sources for detecting an eyeball position.

Reference numeral 50 denotes a control unit for controlling each unit. The X drive unit 41 and the X drive unit 41 receive an instruction signal from the controller 6.
The arm unit 2 is moved by driving the Y drive unit 42 and the Z drive unit 43. Further, an image signal from the CCD camera 24 is input to the image processing unit 51, and an eyeball position is detected from the image signal, and the control unit 50 controls the drive of the aperture moving device 45.

Next, a method of detecting the position of the eyeball according to the present embodiment will be described. FIG. 6 is a diagram showing an anterior segment image of the patient's eye captured by the CCD camera 24, and FIG.
FIG. 7 is a diagram showing a light amount distribution on an AA ′ line in FIG. 6 obtained from an image pickup signal from FIG. As shown in the figure, the light amount differs depending on the pupil, iris, and sclera, so that the pupil edge coordinates in the horizontal direction can be detected from this information, and the center position of the pupil edge is detected from the pupil edge detection, that is, the coordinates of the center of the pupil in the horizontal direction. Can be obtained. Similarly, the coordinates of the center of the pupil in the vertical direction can be obtained. It is preferable that the horizontal and vertical detection lines obtain light amount distribution information of a plurality of lines centered on the center of the image sensor surface of the CCD camera 24, and average them. Further, the position of the center of gravity may be obtained from the entire pupil region. Further, as disclosed in Japanese Patent Application Laid-Open No. 10-192333, the light amount level of the pupil region and the light amount level of the iris region may be obtained, and a threshold level may be set between both to obtain the pupil center.

The operation of the apparatus having the above configuration will be described. The operator inputs various data such as the refractive power of the patient's eye and the operating conditions by using the computer 9. The excision data of the corneal surgery is calculated by the main body of the computer 9 and input to the control unit 50. When the preparations are completed, the surgeon can use the microscope 3
The slit image on the cornea projected from the slit projection optical systems 30a and 30b via the optics is observed, and alignment with the patient's eye is performed.

The alignment by observing the slit image will be described with reference to FIG. Cross slit images are respectively projected onto the cornea by the left and right slit projection optical systems 30a and 30b. When the working distance (the focus position of the microscope unit 3) is in agreement with the positional relationship with the corneal vertex, it is observed as shown in FIG. That is, in the observation visual field, a vertical slit line 37a extending from the left and a vertical slit line 37b extending from the right in the front-rear direction.
Overlap at the apex of the cornea. The line 38 is formed by overlapping a horizontal slit line extending from the left and a horizontal slit line extending from the right. On the other hand, when the cornea is away from the proper working distance, as shown in FIG.
The two vertical slit lines 37a and 37b appear to be separated. When the cornea is closer than the proper working distance, the two vertical slit lines 37a and 37b appear to intersect as shown in FIG. In addition, when the corneal apex is shifted in the front-rear and left-right directions of the observation visual field (the optical axis of the objective lens 20 of the observation optical system) by the microscope unit 3, FIG.
Looks like (e), (f), (g). Note that the alignment using this slit image is basically the same as that of Japanese Patent Application Laid-Open No. 6-47001, so please refer to this for details.

From the observation of the slit image, the surgeon can
As shown in FIG. 5A, the arm 2 is moved by operating the joystick 7 to adjust the horizontal and vertical directions (XY directions), and the observation optical unit 5 is moved up and down by operating the switch 60. To adjust the distance direction.
Since centering during laser irradiation is generally performed at the center of the pupil, fine adjustment in the XY directions is adjusted so that the center of the pupil observed by the microscope unit 3 and a reticle (not shown) have a predetermined relationship. I do.

When the alignment is completed, the controller 6
The upper READY switch 62 is pressed to make the laser irradiation possible. The control unit 50 stores the pupil center position (eyeball position) detected as described above from the output signal from the CCD camera 24 by this signal input as a reference position,
Activate the eye tracking mechanism. The image signal from the CCD camera 24 is processed by the image processing unit 51 and input to the control unit 50, and the control unit 50 obtains the pupil center position. Control unit 5
0 compares the reference position with the pupil center position as needed, and when it is detected that the patient's eye has moved beyond a predetermined allowable range, the aperture moving device 45 (motors 46 and 47) is operated based on the comparison information. By driving control, the aperture 13 is moved two-dimensionally in a plane direction orthogonal to the center optical axis L of the laser irradiation optical axis. Thereby, the irradiation area on the patient's eye cornea limited by the aperture 13 also moves in the two-dimensional XY directions.

FIGS. 8A and 8B are diagrams schematically showing the manner in which the irradiation area moves as the aperture 13 moves. When the aperture 13 is moved in a direction orthogonal to the optical axis (laser irradiation optical axis) L1 of the projection lens 16, the irradiation area 100 of the aperture 13 projected onto the affected area by the projection lens 16 may move with the movement. I understand.

When the operator steps on the foot switch 8 after pressing the READY switch 62, the controller 50
Is driven to emit excimer laser light. The excimer laser light is guided to the above-mentioned laser irradiation optical system and irradiated on the cornea of the patient's eye, and an intended area limited by the aperture diameter of the aperture 13 is ablated by a set amount. During the laser irradiation, the laser irradiation area is moved by tracking the movement of the eyeball based on the eyeball position detection. However, since the laser irradiation area can be moved only by moving the aperture 13,
Quick tracking is possible, and tracking of subtle movements of the patient's eye can be performed well. When the patient's eye moves beyond the moving range of the aperture 13, the control unit 50 inserts a safety shutter (not shown) into the optical path of the laser irradiation optical system,
Cut off laser irradiation.

If the movement of the aperture 13 in the above description is performed from the first alignment, the alignment can be automated. In this case, it can be performed in combination with the movement of the arm 2. That is, the control unit 50 moves the arm unit 2 by driving the X drive unit 41 and the Y drive unit 42 for the rough alignment that needs to be largely moved based on the information of the eyeball position detection by the CCD camera 24, Fine alignment is performed by moving the aperture 13. This way,
Accurate alignment can be quickly performed.

In the above embodiment, tracking is not performed in the Z direction (the direction of the laser irradiation optical axis) because the movement of the patient's eye is small, but when tracking in the Z direction is necessary, the following is performed. Can respond.

For detecting the position of the eyeball, a slit image projected on the cornea by each of the slit projection optical systems 30a and 30b can be used. That is, as shown in FIG. 9, a half mirror 60 is disposed behind the objective lens 20 on the observation optical system side, and a filter 61 for cutting infrared light and a CCD camera 62 are disposed on the reflection side. The image signal from the CCD camera 62 is input to the image processing unit 51, and the image processing unit 61 detects a slit image projected on the cornea. The position detection is based on the relationship between the vertical slit lines 37a and 37b shown in FIG.
By detecting the change amount of the vertical slit lines 37a and 37b in (c), the position of the eyeball shifted in the distance direction (Z direction) can be detected. FIG. 5 also shows the XY directions.
It can be detected from the positional relationship between the vertical slit lines 37a and 37b and the horizontal slit line 38 in (d) to (g). In addition, only the position detection in the Z direction uses the above slit image,
For the XY directions, the pupil position detection information can be used as in the previous example.

Tracking of the laser irradiation area in the Z direction (the laser irradiation optical axis direction) will be described with reference to FIG. It is assumed that the affected part position P1 shown in FIG. 8A has moved to the position P2. If the aperture 13 is moved in the direction of the optical axis L1 in accordance with this change, the projection image of the aperture 13 by the projection lens 16 can be moved. Furthermore, if the aperture diameter of the aperture 13 is changed, the projection lens 16
, The change in the projection magnification caused by changing the distance of the aperture 13 can be corrected. That is, in the example of FIG. 10, the irradiation is performed by moving the aperture 13 toward the projection lens 16 according to the amount by which the affected part position has moved away from the initial position P1 and reducing the aperture diameter of the aperture 13 according to the amount. The area 100 can be moved in the axial direction by the same size. The movement of the aperture 13 in the axial direction is performed by a motor 48 controlled by the control unit 50, and the opening diameter of the aperture 13 is performed by a motor 49. Aperture 1 also moves the irradiation area in the Z direction
3 (and a change in the diameter of the opening), the tracking can be performed quickly.

[0030]

As described above, according to the present invention,
The laser irradiation area can be deviated by moving the restricting member (aperture) for restricting the laser irradiation area without moving the laser irradiation optical system in a large scale. Tracking can be performed quickly.

[Brief description of the drawings]

FIG. 1 is an external view of a corneal surgery apparatus according to an embodiment.

FIG. 2 is a view showing a moving mechanism of an arm unit.

FIG. 3 is a diagram showing an outline of an optical system and a control system of the apparatus.

FIG. 4 is a view showing an aperture moving device.

FIG. 5 is a diagram illustrating alignment by observing a slit image.

FIG. 6 is a diagram illustrating an anterior segment image of a patient's eye captured by a CCD camera, for explaining eyeball position detection.

7 is a diagram showing a light amount distribution on an AA 'line in FIG. 6;

FIG. 8 is a diagram schematically showing a state in which an irradiation area moves by movement of an aperture.

FIG. 9 is a diagram showing a configuration of position detection when a slit image projected on the cornea is used.

FIG. 10 is a diagram illustrating tracking of a laser irradiation area in a Z direction (a laser irradiation optical axis direction).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surgery apparatus main body 2 Arm part 3 Microscope part 4 Illumination part 4 11 Laser light source 13 Aperture 24 CCD camera 30a, 30b Slit projection optical system 45 Aperture moving device 50 Control part 51 Image processing part

Claims (4)

[Claims] 1. A laser operation apparatus including a laser irradiation optical system for irradiating a treatment laser beam to an affected part, a position detecting means for detecting a position of the affected part to be irradiated with the treatment laser light, and the laser irradiation optical system. A limiting member having a variable aperture diameter that limits an irradiation area of the laser beam to the affected part, and a moving unit that moves a position of the limiting member in the laser irradiation optical system, based on a detection result of the position detecting unit. And a control means for drivingly controlling the moving means. 2. A laser operating apparatus according to claim 1, wherein said moving means includes a plane direction moving means for moving said limiting member two-dimensionally in a plane direction orthogonal to a laser irradiation optical axis. Surgical equipment. 3. The laser surgical apparatus according to claim 1, wherein said moving means moves the limiting member two-dimensionally in a plane direction orthogonal to a laser irradiation optical axis, and irradiates the limiting member with laser. An axial moving means for moving in the axial direction of the optical axis, wherein the position detecting means is a detecting means for detecting a three-dimensional position of the affected part, and the control means is based on a detection result of the three-dimensional position by the position detecting means. A laser operating apparatus for controlling the driving of the planar moving means and the axial moving means, and variably controlling the opening diameter of the restricting member when moving the restricting member in the axial direction. 4. The laser surgery apparatus according to claim 1, wherein the laser surgery apparatus is a corneal surgery apparatus that irradiates a cornea of a patient's eye with a laser beam in an ultraviolet region to ablate the cornea.